Standard Specifications for Road, Bridge, and Municipal Construction 2020 (M 41-10)

Culverts 7-02

7-02.3(6)A1 Design Criteria

The precast Structures shall be designed for a minimum service life of 75-years in
accordance with the WSDOT

M 46-03, WSDOT

LRFD M 23-50, and AASHTO LRFD Bridge Design Specifications, latest edition and

current interims in effect on the Bid advertising date, including an HL-93 vehicular live
load. Live load for the Extreme Event-I Limit State shall be applied in accordance with
WSDOT

Bridge Design Manual LRFD

M 23-50 Section 3.5.

PRCSBC shall also be designed in accordance with ASTM C1786.

Precast Structures with an overall span length greater than 20-feet (measured along
the centerline of Roadway from inside face to inside face of hydraulic opening) shall be
designed for seismic loads in accordance with AASHTO Technical Manual for Design and
Construction of Road Tunnels – Civil Elements (2010), Chapter 13. The AASHTO LRFD Bridge
Design Specifications Section 12.6.1 exemption from seismic loading does not apply. The
design shall evaluate the seismic effects of transient racking deformations.

Wingwalls, cutoff walls, and headwalls associated with the precast Structures shall be
designed in accordance with the WSDOT

Geotechnical Design Manual

M 46-03 and

Chapter 11 of AASHTO LRFD Bridge Design Specifications, latest edition and current
interims in effect on the Bid advertising date, including seismic loads.

The Contractor shall use the geotechnical report prepared for this project and available
through the source(s) specified in the Special Provisions under

Section 1-02.4(2)

Whenever the minimum finished backfill or surfacing depth above the top of the
Structure is less than 1’-0” (except when the top of the Structure is directly exposed to
vehicular traffic), either all steel reinforcing bars in the span unit shall be epoxy-coated
with 2" minimum concrete cover from the face of concrete to the face of the top mat of
steel reinforcing bars, or the minimum concrete cover shall be 2½". Whenever the top
of the Structure is directly exposed to vehicular traffic, all steel reinforcing bars in the
span unit shall be epoxy-coated and the minimum concrete cover dimension from face of
concrete to the face of the top mat of steel reinforcing bars shall be 2½". Concrete cover
from the face of any concrete surface to the face of any steel reinforcement shall be
1-inch minimum end clearance at all joints, and 2-inches minimum at all other locations.

7-02.3(6)A2 Submittals

The Contractor shall submit shop drawings of the precast Structures. Fabrication shop
drawings replicating complete design details when shown in the Plans shall be Type 2
Working Drawings. Submittals completing the design based on the schematic geometric
requirements shown in the Plans, or proposing a Contractor designed alternative concrete
culvert Structure shall be Type 2E Working Drawings with supporting design calculations.

Page 7-10

In addition to items 1 through 6 under shop drawing content requirements in

Section

6-02.3(28)A

, the following shop drawing details shall be submitted:

1.  Footing and slab base details for PRCTSS.
2.  Wingwall, headwall, and cutoff wall details.
3.  Erection and backfill procedure.
4.  Complete, site specific, itemized bar list for all steel reinforcement.

If water is expected to be present in the excavation, or is found to be present once
excavation begins, the Contractor shall submit a Type 2 Working Drawing consisting of a
dewatering plan.

For precast Structures with a span length greater than 20-feet (as defined in

Section

7-02.3(6)A1)

, except when the depth of fill above the top of culvert exceeds the Structure

span length, a Type 2E Working Drawing shall be submitted consisting of a load rating
report prepared in accordance with the AASHTO Manual for Bridge Evaluation and

Bridge

Design Manual LRFD

Chapter 13

. Soil pressures used shall include effects from the backfill

material and compaction methods, and shall be in accordance with the

Geotechnical

Design Manual

M 46-03 and the geotechnical report prepared for the project.

7-02.3(6)A3 Casting

Concrete shall conform to

Section 6-02.3(28)B

, with a 28-day compressive strength as

specified in the Plans or the Working Drawings submittal.

7-02.3(6)A4 Excavation and Bedding Preparation

All excavated material shall be disposed of in accordance with

Section 2-09.3(1)D

If water is present within the excavation, the Contractor shall dewater the excavated area
in accordance with the dewatering plan Working Drawing submittal before placing the
bedding material.

The bedding course shall be a 6-inch minimum thickness layer of culvert bedding material,
defined as granular material either conforming to

Section 9-03.12(3)

or to AASHTO

Grading No. 57 as specified in

Section 9-03.1(4)C

. The plan limits of the culvert bedding

material shall extend 1-foot beyond the plan limits of the culvert or the Structure footing
as applicable. The culvert bedding material shall be compacted in accordance with the

Section 2-09.3(1)E

requirements for gravel backfill for drains. After compaction, the

culvert bedding material shall be screeded transversely to the specified line and grade.
Voids in the screeded culvert bedding material shall be filled and then rescreeded prior to
erecting the precast Structure.

Culverts 7-02

7-02.3(6)A5 Wingwalls and Retaining Walls

Wingwalls and retaining walls (including cutoff walls and headwalls) shall be constructed
in accordance with the Contractor’s design and Working Drawing submittal or when
the Plans include a complete set of design details for a wall (defining panel shapes
and dimensions, concrete strength requirements, and steel reinforcing bar, joint, and
connection details), the details shown in the Plans.

Precast concrete construction shall conform to

Sections 6-02.3(28)

and

6-11.3(3)

Culvert bedding material shall be furnished, placed, and compacted in accordance with

Section 7-02.3(6)A4

7-02.3(6)B

Precast Reinf. Conc. Three Sided Structures (PRCTSS)

7-02.3(6)B1

Design Criteria

In addition to the design criteria specified in

Section 7-02.3(6)A1

, the following shall

apply.

PRCTSS shall be precast rigid frames with monolithic upper corners internally reinforced
for moment and shear resistance, except as otherwise noted. Connecting separate and
individually precast concrete panels together to form the specified three sided frame
geometry is acceptable provided the Structure system provides moment and shear
resistance from the lateral load from backfill placed full width and full height at one side
only of the PRCTSS.

7-02.3(6)B2 Finishing

The Contractor shall mark the following information, using waterproof paint, on the inside
of a vertical leg of each precast section of the Structure:
1. PRCTSS span and rise dimensions, minimum and maximum design earth cover

dimensions, and vehicular live load for design (HL-93).

2. WSDOT Contract Number and date of fabrication.
3. Name or trademark of the fabricator.

7-02.3(6)B3 Erection

PRCTSS shall be erected and backfilled in accordance with the erection sequence
specified in the processed Working Drawings, and the construction equipment
restrictions specified in

Section 6-02.3(25)O

Adjacent precast sections shall be connected by welding the weld-tie anchors in
accordance with

Section 6-03.3(25)

. Welding ground shall be attached directly to the

steel plates being welded when welding the weld-ties. The weld-tie anchor spacing shall
not exceed 6’-0”. After connecting the weld-tie anchors, the Contractor shall paint the
exposed metal surfaces with one coat of field primer conforming to

Section 9-08.1(2)F

Keyways shall be filled with grout conforming to

Section 9-20.3(2)

Page 7-12

7-02.3(6)C

Precast Reinf. Conc. Box Culverts (PRCBC) and Precast Reinf.

Conc. Split Box Culverts (PRCSBC)

7-02.3(6)C1 Casting

PRCSBC shall consist of lid elements and “U” shaped base elements. The vertical legs of
the “U” shaped base elements shall be full height matching the rise of the culvert, except
as otherwise specified for culvert spans greater than 20-feet. For PRCSBC spans greater
than 20-feet (as defined in

Section 7-02.3(6)A1

), the lid elements may include vertical legs

of a maximum length of 4-feet.

All vertical and horizontal joints of PRCBC and PRCSBC elements shall be tongue and
groove type joints, except PRCBC and PRCSBC of 20-foot span or less may have keyway
joints connected by weld-tie anchors in accordance with

Section 6-02.3(25)O

. The weld-

tie anchor spacing shall not exceed 6’-0”. There shall be at least two galvanized steel tie
plates across each top unit tongue and groove joint and each tongue and groove joint
between upper and lower units, unless otherwise shown in the Plans or required by the
seismic design completed in accordance with

Section 7-02.3(6)A1

7-02.3(6)C2 Finishing

The following information shall be legibly and permanently marked on one inside face of
each PRCBC element, or one inside face of each PRCSBC “U” shaped base element by
indentation, waterproof paint, or other means acceptable to the Engineer:
1. Box section span and rise dimensions, minimum and maximum design earth cover

dimensions, and vehicular live load for design (HL-93).

2. WSDOT Contract Number and date of fabrication.
3. Name or trademark of the fabricator.

7-02.3(6)C3 Erection

PRCBC and PRCSBC shall be erected and backfilled in accordance with the erection
sequence specified in the Working Drawing submittal, and the construction equipment
restrictions specified in

Section 6-02.3(25)O

The Contractor shall install a continuous strip of butyl rubber sealant within all tongue
and groove joints prior to connecting the precast elements together. The butyl rubber
sealant shall have a minimum cross section of ½-inch by 1½-inch, unless otherwise shown
in the Plans.

After connecting the joints with weld-tie anchors, the Contractor shall paint the exposed
metal surfaces with one coat of field primer conforming to

Section 9-08.1(2)F

. Keyways

shall be filled with grout conforming to

Section 9-20.3(2)

Culverts 7-02

The Contractor shall wrap all exterior joints along the top and sides of the PRCBC and
PRCSBC with a 12-inch wide strip of external sealing band centered about the joint and
adhesively bonded to the concrete surface.

Backfill beside the PRCBC and PRCSBC shall be brought up in sequential layers,
compacted concurrently. The difference in backfill height on opposing sides of the
Structure shall not exceed 2-feet.

7-02.4 Measurement

The length of culvert pipe or pipe arch will be the number of linear feet of completed
installation measured along the invert. Pipe placed in excess of the length designated by
the Engineer will not be measured or paid for.

Beveled end sections will be considered as part of the culvert pipe and shall be measured
as culverts.

Flared steel and aluminum end sections will be measured by the number of integral units
of the dimension specified including toe plate extensions if called for in the Plans.

The pipe connector section of end section Design A shall be fabricated as a part of the
integral unit of the end section but will be measured as linear feet of pipe or pipe arch of
the treatment, thickness and dimensions of pipe to which it is attached. If there is no Bid
item for pipe of the proper dimensions for the end sections, the pipe connector sections
will be considered as part of the integral unit and will not be measured as pipe.

Pipe connector sections of end section Design B will be considered part of the integral
unit and measurement will be by number of integral units of the type and dimension
specified.

The length of safety bars for culvert pipe will be the number of linear feet of each safety
bar installed.

Tapered end section with safety bars will be measured by the unit per each.

Culvert bedding material will be measured by the cubic yard of material placed.

7-02.5 Payment

Payment will be made for each of the following Bid items that are included in the
Proposal:

“Schedule ____ Culv. Pipe ____ In. Diam.”, per linear foot.
“Plain Conc. Culv. Pipe ____ In. Diam.”, per linear feet.
“Cl. ____ Reinf. Conc. Culv. Pipe ____ In. Diam.”, per linear foot.
“Plain St. Culv. Pipe ____ In. Th. ____ In. Diam.”, per linear foot.
“Tr. ____ St. Culv. Pipe ____ In. Th. ____ In. Diam.”, per linear foot.
“Plain St. Culv. Pipe Arch ____ In. Th. ____ In. Span”, per linear foot.

Structural Plate Pipe, Pipe Arch, Arch, and Underpass

7-03

Structural Plate Pipe, Pipe Arch, Arch, and Underpass

7-03.1 Description

This Work consists of constructing structural plate pipe, pipe arches, arches, and
underpasses of the various types and designs in accordance with the Plans, these
Specifications, and the

Standard Plans

, at the locations and in conformity with the lines

and grades staked.

Structural plate pipes shall be full circle of the type, gage or thickness, and diameter
specified.

Structural plate pipe arches shall be a multi-centered shape made up of four circular arcs
tangent to each other at their junctions and symmetrical about the vertical axis and of the
type, gage or thickness, and span specified.

Structural plate arches shall be a single-centered circular arc shape, placed on a reinforced
concrete foundation, and of the design, type, gage or thickness, and span as provided for
in the Plans.

Structural plate underpasses shall be a multi-centered shape made up of a variable
number of circular arcs tangent to each other at their junctions and symmetrical about the
vertical axis and of the design, type, gage or thickness, and span specified.

7-03.2 Materials

Materials shall meet the requirements of the following sections:

Concrete Class 3000

Corrugated Steel

Corrugated Aluminum

Reinforcing Steel

Alternate installations shown in the Proposal may be constructed provided there is no
increase in the total cost of the installation or detriment to the Contracting Agency.

Measurement for payment of the Bid items associated with the drainage installation will
be based on the size of the installation described by the Bid item in the Proposal.

If the Contractor elects to use an alternate installation, Type 2 Working Drawings
consisting of plans for the alternate shall be submitted.

Page 7-16

Structural Plate Pipe, Pipe Arch, Arch, and Underpass

7-03.3

Construction Requirements

7-03.3(1) Foundations, General

Structural plate pipes, pipe arches, underpasses, and bases for arches shall be placed on
stable foundations prepared to the widths, depth, and grade given by the Engineer. Soft
spots encountered in the base shall be excavated to a depth designated by the Engineer
and be backfilled with gravel or other suitable material and thoroughly compacted.

Rock, in either ledge or boulder formation, hard pan, or cemented gravel occurring in the
base material shall be excavated below grade and backfilled with suitable material so
there will be a minimum 8-inch cushion under the pipes, pipe arches, or underpasses.

When aluminum pipe or pipe arch is in contact with cement concrete, two coats of paint
shall be applied in accordance with

Section 7-08.3(2)D

7-03.3(1)A

Structural Plate Pipe, Pipe Arch, and Underpass

The base for structural plate pipes, pipe arches and underpasses shall be shaped to
conform to their bottom and shall form firm and uniform bearing throughout their length.
Where pipes, pipe arches, or underpasses are to be installed in new embankment, the
embankment shall be constructed to the ⅓ point of structural plate pipes (measured from
the invert of the pipe), to the height of maximum horizontal dimension of structural plate
pipe arches and as provided for in the

Standard Plans

or, in the case of a special design, in

the Plans for structural plate underpasses, after which the trench shall be excavated and
installation made.

7-03.3(1)B

Structural Plate Arch

The base for structural plate arches shall be as shown in the Plans.

7-03.3(2) Assembling

Structural plate pipes, pipe arches, arches, and underpasses shall be assembled in place in
accordance with the manufacturer’s instructions, which shall accompany the shipment of
materials and show the position of each plate and the order of assembly.

Bolts and bolted connections shall conform to the requirements of AASHTO M 167 for
steel and AASHTO M 219 for aluminum.

7-03.3(3) Backfilling

After the structural plate pipe, pipe arch, arch, or underpass has been placed in position it
shall be backfilled in accordance with

Section 7-08.3(3)

Structural Plate Pipe, Pipe Arch, Arch, and Underpass

7-03

7-03.3(4) Invert Treatment

Earth, or other material as specified, shall be placed and compacted in the invert of
structural plate pipes, pipe arches, or underpasses in conformance with the Plans, Special
Provisions, or the

Standard Plans

7-03.3(5) Headwalls

If headwalls are specified in the Plans, they shall be constructed as soon as the
embankment has been completed to a sufficient height over the Structure to allow the
required Work. Headwalls shall be constructed in accordance with the applicable portions
of

Section 6-02

When aluminum pipe or pipe arch is in contact with cement concrete, two coats of paint
shall be applied in accordance with

Section 7-08.3(2)D

7-03.3(6) Safety Bars for Culvert Pipe

When shown in the Plans, safety bars for culvert pipe shall be constructed in accordance
with the

Standard Plans

and shall meet the requirements of

Section 9-05.18

7-03.4 Measurement

The length of structural plate pipes, pipe arches, arches, and underpasses will be the
number of linear feet of completed installation measured along the invert. Pipe placed in
excess of the length designated by the Engineer will not be measured or paid for.

Concrete will be measured by the cubic yard as specified in

Section 6-02

Steel reinforcing bars will be measured by the pound as specified in

Section 6-02.

Structure excavation Class B and Structure excavation Class B including haul will be
measured by the cubic yard as specified in

Section 2-09.4.

Gravel backfill for foundation Class A or Class B will be measured by the cubic yard as
specified in

Section 2-09.4

Shoring or extra excavation will be measured as specified in

Section 2-09.4

The length of safety bars for culvert pipe will be the number of linear feet of each safety
bar installed.

Tapered end Section with safety bars will be measured by the unit per each.

Page 7-18

Structural Plate Pipe, Pipe Arch, Arch, and Underpass

7-03.5 Payment

Payment will be made for each of the following Bid items that are included in the
Proposal:

“St. Str. Plate Pipe ____ Gage ____ In. Diam.”, per linear foot.
“St. Str. Plate Pipe Arch ____ Gage ____ Ft. Span”, per linear foot.
“St. Str. Plate Arch ____ Gage ____ Ft. Span”, per linear foot.
“Design ____ St. Underpass ____ Gage ____ Ft. Span”, per linear foot.
All costs involved in obtaining, hauling, placing, and finishing earth to be placed in
the invert of the underpass shall be included in the unit Contract price for “Design
____ St. Underpass ____ Gage ____ Ft. ____ In. Span”.
“Al. Str. Plate Pipe ____ In. Th. ____ In. Diam.”, per linear foot.
“Al. Str. Plate Pipe Arch ____ In. Th. ____ Ft. ____ In. Span”, per linear foot.
“Al. Str. Plate Arch ____ In. Th. ____ Ft. ____ In. Span”, per linear foot.
“Design ____ Al. Underpass ____ In. Th. ____ Ft. ____ In. Span”, per linear foot.
All costs involved in obtaining, hauling, placing, and finishing earth to be placed in
the invert of the underpass shall be included in the unit Contract price for “Design
____ Al. Underpass ____ In. Th. ____ Ft. ____ In. Span”.
“Conc. Class ____”, per cubic yard.
The unit Contract price per cubic yard for “Conc. Class ____” shall be paid as
specified in

Section 6-02

“St. Reinf. Bar”, per pound.
The unit Contract price per pound for “St. Reinf. Bar” shall be paid as specified in

Section 6-02

“Structure Excavation Class B”, per cubic yard.
“Structure Excavation Class B Incl. Haul”, per cubic yard.
“Gravel Backfill for Foundation Class ____”, per cubic yard.
“Shoring or Extra Excavation Class B”, per square foot.
“Safety Bars for Culvert Pipe Type ____”, per linear foot.
“Tapered End Section with Type ____ Safety Bars ____ In. Diam.”, per each.
“Tapered End Section with Type ____ Safety Bars ____ In. Span”, per each.

Storm Sewers

7-04

Storm Sewers

7-04.1 Description

This Work consists of constructing storm sewer lines in accordance with the Plans, these
Specifications, and the

Standard Plans

, as staked.

7-04.2 Materials

Materials shall meet the requirements of the following sections:

Plain Concrete Storm Sewer Pipe

9-05.7(1)

Reinforced Concrete Storm Sewer Pipe

9-05.7(2)

Steel Spiral Rib Storm Sewer Pipe

9-05.9

Steel Storm Sewer Pipe

9-05.10

Aluminum Storm Sewer Pipe

9-05.11

Solid Wall PVC Storm Sewer Pipe

9-05.12(1)

Profile Wall PVC Storm Sewer Pipe

9-05.12(2)

Aluminum Spiral Rib Storm Sewer Pipe

9-05.17

Corrugated Polyethylene Storm Sewer Pipe

9-05.20

Steel Rib Reinforced Polyethylene Storm Sewer Pipe

9-05.22

High-Density Polyethylene (HDPE) Pipe

9-05.23

Polypropylene Storm Sewer Pipe

9-05.24

Where steel or aluminum are referred to in this section in regard to a kind of storm sewer
pipe, it shall be understood that steel is zinc coated (galvanized) or aluminum coated
(aluminized) corrugated iron or steel and aluminum is corrugated aluminum alloy as
specified in Sections

9-05.4

and

9-05.5

Thermoplastic storm sewer pipe includes solid wall PVC storm sewer pipe, profile wall
PVC storm sewer pipe, corrugated polyethylene storm sewer pipe, and polypropylene
storm sewer pipe.

Measurement for payment of the Bid items associated with the storm sewer installation
will be based on the diameter of the storm sewer pipe described by the Bid item in the
Plans.

It is not necessary that all storm sewer pipe on any one project be of the same kind of
material. However, all contiguous pipe shall be of the same size, material, thickness, class,
and treatment and shall be that required for the maximum height of cover.

When schedule A or B storm sewer pipe is specified in the Plans, the Contractor shall
provide the specified schedule and diameter but has the option of furnishing any of the
acceptable materials shown in the Storm Sewer Pipe Schedules Table.

7-04.3

Construction Requirements

Storm sewers shall be constructed in accordance with

Section 7-08.3

Page 7-20

Storm Sewers

7-04.3(1) Cleaning and Testing

7-04.3(1)A General

The requirements of

Section 7-17.3(2)A

shall apply to storm sewers.

7-04.3(1)B

Exfiltration Test – Storm Sewers

Prior to making exfiltration leakage tests, the Contractor may fill the pipe with clear water
to permit normal absorption into the pipe walls.

Leakage shall be no more than 1 gallon per hour per inch of diameter per 100 feet of
storm sewer pipe, with a minimum test pressure of 6 feet of water column above the
crown at the upper end of the pipe or above the active ground water table, whichever is
higher as determined by the Engineer. The length of pipe tested shall be limited so that
the pressure on the invert of the lower end of the Section tested shall not exceed 16 feet
of water column. For each increase in pressure of 2 feet above a basic 6 feet measured
above the crown at the lower end of the test section, the allowable leakage shall be
increased by 10 percent.

Storm Sewer Pipe Schedules

Aluminum

Schedules

(Fill Ht.)

Dia.

(In.)

Concrete

PVC

Steel

2⅔″ × ½″

or Spiral Rib

2⅔″ × ½″ Corr.

•

Tr. 5

•

Plain With

Gasketed Seams

Spiral Rib

•

Tr. 5

•

Plain With

Gasketed Seams

2′ − 15′

Plain or Cl. IV

SW or PW Allowed

0.064″ (16 Ga.)

0.060″ (16 Ga.)

Plain or Cl. IV

SW or PW Allowed

0.064″ (16 Ga.)

0.060″ (16 Ga.)

Plain or Cl. IV

SW or PW Allowed

0.064″ (16 Ga.)

0.060″ (16 Ga.)

Class III

Allowed

0.064″ (16 Ga.)

0.075″ (14 Ga.)

0.060″ (16 Ga.)

Class III

Allowed

0.064″ (16 Ga.)

0.075″ (14 Ga.)

0.060″ (16 Ga.)

Class III

Allowed

0.064″ (16 Ga.)

0.105″ (12 Ga.)

0.075″ (14 Ga.)

Class III

Allowed

0.064″ (16 Ga.)

0.105″ (12 Ga.)

0.075″ (14 Ga.)

15′ − 25′

Class V

SW or PW Allowed

0.064″ (16 Ga.)

0.060″ (16 Ga.)

Class V

SW or PW Allowed

0.064″ (16 Ga.)

0.060″ (16 Ga.)

Class V

SW or PW Allowed

0.064″ (16 Ga.)

0.060″ (16 Ga.)

Class V

Allowed

0.064″ (16 Ga.)

0.075″ (14 Ga.)

Class V

Allowed

0.064″ (16 Ga.)

0.075″ (14 Ga.)

0.105″ (12 Ga.)

Class V

Allowed

0.064″ (16 Ga.)

0.105″ (12 Ga.)

Class V

Allowed

0.064″ (16 Ga.)

0.105″ (12 Ga.)

PVC = Polyvinyl Chloride Pipe, SW = Solid Wall PVC, PW = Profile Wall PVC

PE = Corrugated Polyethylene Pipe

Steel pipe options for either 2⅔″ × ½″ corrugations or spiral rib include: Tr. 5 galvanized, Tr. 2 galvanized with gasketed seams,

Tr. 5 aluminized, or plain aluminized with gasketed seams.

PP = Polypropylene Pipe, 12 inch to 30 inch approved for Schedule A and Schedule B and 36 inch to 60 inch diameters

approved for Schedule A only.

Storm Sewers

7-04

7-04.3(1)C

Infiltration Test – Storm Sewers

Whenever the ground water table is above the crown of the higher end of the pipe
section at the time of testing, an infiltration test may be performed in lieu of the
exfiltration test upon written permission of the Engineer. The maximum allowable limit for
infiltration shall be 0.8 gallon per hour per inch of diameter per 100 feet of length with no
allowance for external hydrostatic head.

7-04.3(1)D

Other Test Allowances – Storm Sewers

Other allowances for infiltration and exfiltration tests shall be in accordance with

Section 7-17.3(2)D

7-04.3(1)E

Low Pressure Air Test for Storm Sewers Constructed of Air

Permeable Materials

When air permeable pipe is subjected to a low-pressure air test, all of the provisions of

Section 7-17.3(2)E

shall apply, except that the time in seconds for the pressure drop shall

be equal to or greater than the required time as shown in the table below:

Time in Seconds for Pressure Drop

Pipe

Dia. (in)

Pipe Length (ft)

100

150

200

250

300

350

400

450

500

107

114

111

139

142

143

159

120

160

170

183

206

228

125

188

213

214

250

286

320

360

180

255

257

310

360

410

460

520

123

245

298

350

420

490

560

630

700

160

320

340

370

460

550

640

730

830

920

203

390

460

580

700

810

930

1040

1160

250

430

570

720

860

1000

1140

1290

1430

All time values listed in the table are in seconds. If a section to be tested includes more
than one pipe size, the total time required can be found by adding the time values for
each size of pipe and its corresponding length. Interpolate between valves for pipe
lengths not shown.

Pipe over 30 inches in diameter shall be tested one joint at a time in accordance with
ASTM C1103.

Page 7-22

Storm Sewers

7-04.3(1)F

Low Pressure Air Test for Storm Sewers Constructed of Non Air

Permeable Materials

When non air permeable pipe is subjected to a low-pressure air test, all of the provisions
of

Section 7-17.3(2)E

shall apply, except that the time in seconds for the pressure

drop shall be equal to or greater than four times the time shown in the table listed in

Section 7-04.3(1)E

Pipe over 30 inches in diameter shall be tested one joint at a time in accordance with
ASTM C1103.

Reaches of thermoplastic pipe containing no joints shall be exempt from testing
requirements.

7-04.4 Measurement

The length of storm sewer pipe will be the number of linear feet of completed installation
measured along the invert and will include the length through elbows, tees, and fittings.
The number of linear feet will be measured from the center of manhole to center of
manhole or to the inside face of catch basins and similar type Structures.

The length of testing storm sewer pipe in conformance with

Section 7-17.3(2)A

will be

the number of linear feet of completed installation actually tested.

7-04.5 Payment

Payment will be made for each of the following Bid items that are included in the
Proposal:

“Plain Conc. Storm Sewer Pipe ____ In. Diam.”, per linear foot.
“Class ____ Reinf. Conc. Storm Sewer Pipe ____ In. Diam.”, per linear foot.
“Tr. ____ St. Storm Sewer Pipe ____ In. Th. ____ In. Diam.”, per linear foot.
“Tr. ____ Al. Storm Sewer Pipe ____ In. Th. ____ In. Diam.”, per linear foot.
“Solid Wall PVC Storm Sewer Pipe ____ In. Diam.”, per linear foot.
“Profile Wall PVC Storm Sewer Pipe ____ In. Diam.”, per linear foot.
“Corrugated Polyethylene Storm Sewer Pipe ____ In. Diam.”, per linear foot.
“Schedule ____ Storm Sewer Pipe ____ In. Diam.”, per linear foot.
“St. Rib Reinf Polyethylene Storm Sewer Pipe ____ In. Diam”, per linear foot.
“High-Density Polyethylene (HDPE) Pipe ____ In. Diam.”, per linear foot.
“Polypropylene Storm Sewer Pipe ____ In. Diam.”, per linear foot.
The unit Contract price per linear foot for storm sewer pipe of the kind and size
specified shall be full pay for all Work to complete the installation, including
adjustment of inverts to manholes.
“Testing Storm Sewer Pipe”, per linear foot.

Manholes, Inlets, Catch Basins, and Drywells

7-05

Manholes, Inlets, Catch Basins, and Drywells

7-05.1 Description

This Work consists of constructing manholes, inlets, drywells, and catch basins and
connecting to existing Structures of the types and sizes designated in accordance with
the Plans, these Specifications, and the

Standard Plans

, in conformity with the lines and

grades staked.

7-05.2 Materials

Materials shall meet the requirements of the following sections:
Concrete

6-02

Crushed Surfacing Base Course

9-03.9(3)

Gravel Backfill for Drywells

9-03.12(5)

Rubber Gaskets

9-04.4

Flexible Plastic Gaskets

9-04.5

Metal Castings

9-05.15

Grate Inlets and Drop Inlets

Reinforcing Steel

Concrete Blocks

Concrete Brick

Precast Concrete Manhole

9-05.50(2)

Precast Concrete Catch Basins

9-05.50(3)

Precast Concrete Inlets

9-05.50(4)

Precast Concrete Drywells

9-05.50(5)

Underground Drainage Geotextile, Moderate Survivability

9-33.1

Mortar

9-20.4

7-05.3

Construction Requirements

The excavation for all manholes, inlets, and catch basins shall be sufficient to leave 1 foot
in the clear between their outer surfaces and the earth bank.

The excavation for drywells shall be in accordance with the

Standard Plans

. The drywell

and gravel backfill for drywell shall be completely encased in moderate survivability
underground drainage geotextile in accordance with the

Standard Plans

and in

conformance with

Section 2-12.3

. During construction of the drywell, all necessary

precautions shall be taken to prevent debris and eroded material from entering
the drywell.

The cover or grating of a manhole, catch basin, or inlet shall not be grouted to final grade
until the final elevation of the pavement, gutter, ditch, or sidewalk in which it is to be
placed has been established, and until permission thereafter is given by the Engineer to
grout the cover or grating in place. Covers shall be seated properly to prevent rocking.
Leveling and adjustment devices that do not modify the structural integrity of the metal
frame, grate or cover, and do not void the originating foundry’s compliance to these
specifications and warranty are allowed. Leveling and adjusting devices that interfere

Page 7-24

Manholes, Inlets, Catch Basins, and Drywells

with the backfilling, backfill density, grouting and asphalt density will not be allowed. The
hardware for leveling and adjusting devices shall be completely removed when specified
by the Engineer.

The channels in manholes shall conform accurately to the sewer grade.

Ladder rungs shall be grouted in the precast concrete walls. Rungs shall be uniformly
spaced at 12 inches and be vertically aligned.

In the event any pipe enters the manhole through the precast concrete units, the
Contractor shall make the necessary cut through the manhole wall and steel mesh. The
steel shall be cut flush with the face of the concrete and shall be cut in such a manner
that it will not loosen the reinforcement in the manhole wall.

The ends of all pipes shall be trimmed flush with the inside walls.

Rubber gaskets or flexible plastic gaskets may be used in tongue and groove joints of
precast units. Joints between precast manhole units used for sanitary sewers shall be
rubber gasketed. All other joints and all openings cut through the walls shall be grouted
and watertight. Mortar shall conform to the requirements of

Section 9-20.4(3)

If gaskets are used, handling of the precast units after the gasket has been affixed shall
be done carefully to avoid disturbing or damaging the gasket or contaminating it with
foreign material. Care shall be exercised to attain proper alignment before the joints
are entirely forced home. During insertion of the tongue or spigot, the units shall be
partially supported to minimize unequal lateral pressure on the gasket and to maintain
concentricity until the gasket is properly positioned.

Rigid pipes connecting to sanitary sewer manholes shall be provided with a flexible joint
at a distance from the face of the manhole of not more than 1½ times the nominal pipe
diameter or 18 inches, whichever is greater.

Flexible pipes connecting to sanitary sewer manholes shall be provided with an entry
coupling or gasket approved by the Engineer. No pipe joint in flexible pipe shall be placed
within 10 feet of the manhole.

Backfilling around the Work will not be allowed until the concrete or mortar has
thoroughly set.

Catch basins, manholes, and inlets shall be watertight.

Catch basin, grate inlet, and drop inlet connections to a sewer shall be so placed that the
connecting pipe may be easily rodded over its entire length. After the connections are
made, the Contractor shall rod all inlet and outlet pipes. All connections that cannot be
successfully rodded shall be removed and new connections made.

Backfilling of manholes, inlets, catch basins, and drywells shall be done in accordance with
the provisions of

Section 2-09

Standard Specifications for Road, Bridge, and Municipal Construction 2020 (M 41-10) - page 74